Ignition distributor



06L 17, 1939. J 1 ARTHUR 2,176,164

IGNITION DI STRIBUTOR Filed April 4, 1938 3 Sheets-Sheet l v .96 8/ .9/Z 90 Z .94 80 Ii 50x O [VJULflT/O/Y ri 3 I as 3 I a3 2; 32 f;

f INVENTOR ATTORNEW 0a. 17, 1939. J, RTH R 2,176,164

IGNITION DISTRIBUTOR Filed April 4, 1958 5 Sheets-Sheet 2 48 v \d i 4720 INVENTOR 40 fmw BY A'ITORNEY,6L

Oct. 17, 1939. J. L. ARTHUR IGNITION DISTRIBUTOR Filed April 4, 1938 3Sheets-Sheet 5 ?E TOR 1% ATTORNEY/Q.

Patented Oct. 17, 1939 UNITED STATES PATENT OFFICE IGNITION DISTRIBUTORApplication April 4, 1938, Serial No. 199,881

3 Claims.

This invention relates to ignition distributors for internal combustionengines.

An object of the invention includes provisions for maintainingconcentricity between the movable breaker plate and the adjustablebreaker plate which carries the ignition circuit interrupter or timerand the shaft of the cam which operates the timer. Where relativelygreat accuracy of ignition timing is a requirement, it is neces- 10 sarythat the adjustable circuit breaker plate be rotated accurately abouttheaxis of the timer cam shaft so that the relation between the shaftand the circuit breaker will be maintained constant for all positions ofadjustment of the ciru. cult breaker plate. In order to accomplish thisobject, I journal that portion of the timer cam shaft which is adjacentthe'cam in a ball bearing of conventional construction. The inner raceof the ball bearing fits snugly around the cam shaft and the outer raceis journaled for rotation in a recess provided by the distributorhousing. The outer race is clamped between two members, one of which isthe circuit breaker supporting plate. These clamping members providemeans for locating the outer bearing race in a fixed position centrallyof these members. In this Way the breaker plate is supported forrotation about the axis of the ball bearing and therefore about the axisof the cam shaft. 39 Further objects and advantages of the presentinvention will be apparent from the following description, referencebeing had to the accompanying drawings wherein a preferred embodiment ofthe present invention is clearly shown.

In the drawings: Fig. 1 is a longitudinal sectional view of an ignitiondistributor embodying the present invention. Fig. 2 is a plan viewthereof with the distributor cover removed taken on the line 22 ofFig. 1. Figs. 3 and 4 are sectional views taken respectively on thelines 3--3 and 44 of Fig. 1.

Fig. 5 showsin perspective a disassembled group of parts including thecircuit breaker plate, ball bearing and ignition timer housing. 45 Theignition distributor comprises housing members and 2| which are securedtogether by screws 22. Member 20 has a shank 23 which is adapted toextend through a bore into the engine frame and is to be secured theretoby a frame of an engine, not shown, to which is secured the shoulders24, a plate 25 upon which rests an adjustable plate 26 which is securedto the housing member 20. Plate 26 is provided with elongated openings21 which provide clearance for the 65 heads of shoulders 24. The plate26 is secured to the plate 25 in various positions of adjustment bymeans of clamping screws 28 cooperating with nuts 29. Screws 28 passthrough arcuate holes, in the plate 26, these holes being concentricwith the axis of the shank 23. Shank 23 supports aball bearing 30 inwhich a shaft 3| is journaled. Shaft 3| carries a gear 32 which mesheswith a gear, not shown, driven by the engine. Shaft 3| has a tubularpart 3 M. which receives the lower end 32a of a timer cam shaft 32, theupper end 32b of which fits into the inner race 33a of a ball bearing33. The outer race 33b is journaled for rotation within a recess 34provided by the bottom wall 35 of the housing 2|. Recess 34 is boundedby an annular boss 36, see Figs. 1 and 5, segmental bosses 31 which areinterrupted by pockets 38. The inner cylindrical surfaces of the arcuatebosses 31 are machined to provide a smooth running fit with the outerrace 33b of the ball bearing 33.

The shafts 3| and 32 are connected by a means located within the housing20, and vary the annular relation between the shafts 3| and 32 inresponse to speed. This speed responsive means comprises, as shown inFigs. 1 and 3, a weight plate secured to the upper end of the shaftportion 3|a and supporting studs 4| upon which weight members 42 arepivoted. Weights 42 are provided with arms 42a engageable with arms 43aof plates 43 secured to the shaft 32. Springs 44 are attached to studs4| and to studs 45 attached to the arms 43a to restrain outwardmovements of the weights 42 due to centrifugal force. The weights 42 areconfined between the plate 40 and a cover plate 46 supported upon studs41 which cooperate with nuts 48 to secure the cover 46 in position.

Referring to Fig. 1, it will be noted that the outer bearing race 33b isclamped between a circuit breaker plate 50 and a clamping plate 5|. Asshown in Fig. 5, plate 50 is provided with three equi-distant tanks 52which fit snugly around the outer race 33b in order to locate the plate50 coaxially with the bearing 33. The clamping plate 5| is provided withthree equi-distant lugs 53 which also fit around the bearing race 33b inorder to locate the plate 5| coaxially with respect to the bearing 33.The lugs 53 have inturned ends 53a which are shaped to engage the bottomend surface of the bearing race 33b as viewed in the drawings. Theplates 50 and 5| and the bearing 33 are secured together by screws 54which pass through plain holes 55 in the plate 50 and which engagethreaded holes 56 in the plate 5|. When the screws 54 are tightened, the

bearing race 33b will be securely clamped between the plates 59 and 5Iwhich are then located coaxially with respect to the bearing 33. Thepockets 38 provided in the housing member 2| are substantially widerthan the lugs 53 and the plate 5| in order to provide for limitedmovement of the plate 50 with respect to the housing 2I. By virtue ofthis construction an antifriction bearing of the conventional type usedto support the timer cam shaft is utilized also to support the circuitbreaker plate and thus maintain it concentrically with respect to theshaft in all positions of adjustment of the circuit breaker plate.

Referring to Fig. 2, the circuit breaker plate 59 is adjusted by adevice which operates in response to variations in suction in the engineintake manifold. This device includes a suction chamber 60 locatedbetween a cup-shaped housing member BI and a flexible diaphragm 62 whichtogether with the member 6! is secured in the periphery to a member 93attached to a bracket 64 which is attached by screws 65 to the housing 2I. The diaphragm is urged into the normal position shown in Fig. 2 byspring 66 bearing at its upper end against a washer 9! and at its lowerend against a shoulder (not shown) provided in a tubular part 68 withwhich the engine intake manifold is connected by a pipe (not shown). Thewasher 6! and the diaphragm 62 are secured by rivet 69 to an arm I0having a pivotal connection with the plate 50 provided by screw II. Asthe engine intake suction varies, the position of the diaphragm 62 andplate 59 will be varied in order to adjust the timing of the ignitionautomatically in accordance with the requirements of the engine.

To the upper end of the cam shaft 32 is secured the ignition timer camwhich in turn supports and drives a distributor rotor BI whichcooperates with inserts in a distributor cap 82 in the usual manner. Cam80 cooperates with one or more circuit interrupters. Fig. 2 shows twocircuit interrupters connected in parallel. Each interrupter includes alever 99 pivoted at SI and carrying a contact 92 movable into and out ofengagement with a contact 93 carried by stationary contact bracket 94supported by the plate 59. Each lever 99 is insulatingly supported byits pivot stud BI and carries a non-conducting rubbing block 95engageable with the cam 89. A leaf spring conductor 96 conducts currentfrom a terminal conductor 91 to the lever and urges the rubbing blocktoward the cam 89 and the contact 92 toward the contact 93. The pivotstud 9| of the stationary bracket of the lower circuit interrupter asviewed in Fig. 2 are mounted directly upon the plate 59. Thecorresponding members of the upper circuit interrupter are mounted uponauxiliary plate 93 which is adjustably mounted upon the plate 50 and ismaintained in concentric relation thereto. To accomplish this, the plate99 is provided with a center annular flange 99 which extends into thecentral opening I09 of the plate 59 (see Fig. 5). Each stationarycontact bracket 94 is adjustable about its companion pivot stud 9| andmay be secured in the desired position of adjustment in. theconventional manner. Likewise the plate 98 is adjusted with respect tothe plate 50 and is secured in the desired position of adjustmentrelative thereto.

A condenser, the case of which is indicated by numeral IUI in Fig. 2 issecured tothe distributor housing and provides a terminal I92 connectedon the inside of the condenser case IIlI with one of the condenserfoils, the other condenser foil being grounded on the case which isgrounded on the distributor housing. A wire I03 connects the terminalI02 with the upper terminal 91 within the distributor housing and a wireI04 connects the upper terminal 91 with the lower terminal 91. In thisway the two circuit breaker levers are connected with the singleinsulated terminal I02 and the circuit interrupters are thus connectedin parallel, the levers 90 being insulated and the stationary contacts93 being grounded.

In the arrangement shown in Fig. 2, the rubbing blocks 95 arediagrammatically opposite. This relation has been secured by anadjustment of the plate 98 relative to the plate 59. This is desirablein order to cause the pairs of interrupter contacts to separate at thesame time, thus dividing up the primary current at break between twosets of contacts. This relation between the circuit interrupters havingonce been established, it is desirable that it be maintained for anyposition of the circuit breaker plate 50 to which it may be moved by thedevice responsive to engine intake suction. By reason of the connectionof the plate 50 with the outer bearing race 331), it is apparent thatconcentricity of movement of the plate with respect to the cam 89 ismaintained. Therefore, for all positions of the plate 50, the rubbingblocks 95 will always be located diametrically opposite with respect tothe cam 80 and their normal distance with respect to the center of thecam 80 will remain equal assuming that the wear on the two rubbingblocks 95 is the same.

While the embodiment of the present invention as herein disclosed,constitutes a preferred form, it is to be understood that other formsmight be adopted, all coming within the scope of the claims whichfollow.

What is claimed is as follows:

1. An ignition distributor for internal combustion engines comprising ahousing, an antifriction bearing having its outer race rotatablyjournaled in the housing, a shaft carrying a timer cam and fixed withinthe inner race, a circuit breaker plate engaging an end surface of theouter race, a sub-plate attached to the breaker plate and engaging theopposite end surface of the outer race, means for securing the sub-plateto the breaker plate whereby the outer race is clamped between the twoplates, a circuit breaker supported upon the breaker plate and having anarm operated upon by the cam; and means for adjusting the breaker plate,said plate rotating coaxially with respect to the cam by reason of theattachment of the plate to the bearing outer race.

2. An ignition distributor according to claim 1 in which the breakerplate is provided with tangs which extend along the outer cylindricalwall of the outer bearing race in order to locate the breaker platecentrally of the race.

3. An ignition distributor according to claim 1 in which the sub-plateis provided with spaced lugs which extend along the outer cylindricalwall of the outer bearing race and extend also in engagement with thatend surface of the race remote from the end surface of the race whichreceives the circuit breaker plate.

JAMES L. ARTHUR.

